Here is a piece of sandstone which has fine layers (about 1mm thick) of different colors. Some individual grains of sand can be seen. This rock makes us wonder what process could produce such fine layers of different colors? The rock was one of a truckload of landscaping river rock in Boulder County, Colorado.
Equipment used: Canon EOS Rebel T5i with a standard zoom lens (EF-S 18-55 mm) on a 49 mm long extension tube.